sinsear, m. (gs. & npl. -sir, gpl. ~).1. Senior, elder. An ~ agus an sóisear, the elder and the younger. ~ an teaghlaigh, the senior member of the family. ~ a clainne, the first-born of her children. ~ na saoithe, the doyen of the learned men. Rang na ~, the senior class. S.a. abhcóide, barra13, braon 1. 2. Ancestor, progenitor. Ár sinsir romhainn, our fathers before us. Mo sheacht ~, my forebears from time immemorial. S.a. peaca.